It is known from WO 2005/062432 A1 that liquid metal alloys can be used instead of the conventional copper slip ring contacts. To this end a current transmission surface is provided respectively on the fixed part and on the part rotating in relation thereto, with the two current transmission surfaces forming a gap between one another, into which the liquid metal alloy is inserted. This creates an electrical contact and at the same time does not restrict the rotatability of the rotating part in relation to the fixed part.
WO 2005/062432 A1 only discloses the transmission of a feed current via three current transmission contact units isolated galvanically from one another.